Carton sealing machines



15 Sheets-Sheet 1 Filed Oct 5, 1965 IN V EN TOR. Ke/me f/7 6. 60.6 0/67 Fig. 1

' F'Lled Oct '5, 1965 15 Sheets-Sheet 2 INVENTOR. Kennefh C. Goba/ef Fig. 2

g- 2, 1966 K. c. GOBALET 3,263,398

CARTON SEALING MACHINES F'Lled Oct 5, l963 15 Sheets-Sheet 3 IN V EN TOR. Ken/7e ff) 6. Goba/ef BY W W ATTORNEY Aug. 2, 1966 K. c. GOBALET 3,263,398

CARTON SEALING MACHINES Filed Oct 5, 1963. 15 Sheets-Sheet 4 IN VEN TOR. Kennef/v C. Goba/ef ATTORNEY K. C. GOBALET CARTON SEALING MACHINES Aug. 2, 1966 15 Sheets-Sheet 5 FLLed Oct 5, 1963 INVENTOR. Kennef/i C. Gbba/ef ATTORNEY AugfZ, 1966 K. c. GOBALET CARTON SEALING MACHINES l5 Sheets-Sheet 6 FLled Oct 3, 1963 Fig. 6

INVENTOR. Kennef/v C Gaba/ef A TTORNEY Aug. 2, 1966 K. c. GOBALET CARTON SEALING MACHINES l5 Sheets-Sheet 7 Filed Oct 5, 1963 JNVEN'TOR. Ken/762% C. bba/ef M ATTORNEY g- 2, 1966 K. c. GOBALET 3,263,398

CARTON SEALING MACHINES Filed Oct 5, 1963 15 Sheets-Sheet 8 Fig. 8

IN V EN TOR. Ken/7e 7/7 6", Goba/e 7 Aug. 2, 1966 K. c. GOBALET 3,253,398

' CARTON SEALING MACHINES Filed 001;. 5, 1965 15 Sheets-Sheet 9 IN VEN TOR. Ken/7e 7/; C. Gaba/ef ATTORNEY Aug. 2, 1966 K. c. GOBALET CARTON SEALING MACHINES 15 Sheets- Sheet 10 Filed Oct 5, 1963 IN VEN TOR. Kenneth 6. 6060/27 A TTOR/VEY 2, 1966 K. c. GOBALET 3,263,398

CARTON SEALING MACHINES F'lled Oct 3, 1963 15 Sheets-Sheet 11 INVENTOR. Fig. Kennef/z CI Gab a/ef Aug. 2, 1966 K. c. GOBALET CARTON SEALING MACHINES 15 Sheets-Sheet 12 Filed Oct 5, 1963 IN V EN TOR. Kennel-h C. Goba/ef I A TTORNEY K. C. GOBALET CARTON SEALING MACHINES Aug. 2, 1966 15 Sheets-Sheet 13 Filed Oct 5. 1963 Fig. /3

INVENTOR. kennef/J C. Goba/ef ATTORNEY Aug. 2, 1966 K. C. GOBALET CARTON SEALING MACHINES Filed 001'. 5, 1963 15 Sheets-Sheet l4 INVENTOR. Xennef/z C. Goba/ef ATTORNEY Aug. 2, 1966 K. c. GOBALET 3,263,393

I CARTON SEALING MACHINES Filed Oct 5, 1963 15 Sheets-Sheet 15 IN V ENTOR. Kennef/v CI Goba/ef 4M ATTORNEY United States Patent 3,263,398 CARTUN SEALING MACHINES Kenneth Clyde Gobalet, Redwood City, Calif., assignor, by inesne assignments, to Kliklolr Corporation, New York, N .Y., a corporation of Delaware Filed Oct. 3, 1963, Ser. No. 313,579 12 Claims. (Cl. 53-376) This invention relates to improvements in machines for sealing cartons or folding boxes by adhesively securing to the carton sides one or several cover flaps articulated to the carton cover. Such flaps are generally referred to in the art as charlottes, if the flaps are articulated to the side of the cover, and are termed front flaps if articulated to the front of the cover. Most common are the style of cartons or boxes in which one or three flaps are provided on the cover.

Cartons and boxes of the aforementioned type are particularly well suited for the packaging of frozen foods. Occasionally the carton contents are irregularly shaped and tend to distort the carton or bulge out one or several walls. Misshapen cartons are difficult to seal securely, are unsightly, and cause ditficulties in the subsequent handling, particularly if such carton are to be tightly overwrapped.

It is for this reason desirable to minimize the effects on the carton sealing procedure of irregularly shaped contents, so as to produce accurately square sealed cartons regardless of whether they contain spinach or broccoli, to mention two representative contents, the first representing a type which conforms readily to the shape of the carton, the second representing a type tending to distort, or produce bulges in, the carton.

For the purpose of sealing the carton it is convenient to apply adhesive to the cover flaps while the flaps are still extended and then to elevate the carton into the throat of a die in which the flaps are folded against the sides of the carton and compressive force is exerted against the sides for a period sutficient to permit the adhesive to set. This is conventional procedure.

If now the carton contain irregular shaped merchandise bearing against the carton bottom and also against the sides, the carton body is likely to be twisted out of shape as well as incompletely sealed.

According to one of the features of this invention this is prevented by supporting the carton in such a way that a load which is locally concentrated in one or several areas of the bottom does not perm-it a side wall to be raised or depressed. For this purpose the carton body is supported adjacent an edge or boundary, leaving the center of the bottom free to assume a lower position. It is also preferred to support the opposite rear wall of the carton by suspending it. This is possible with cartons fitted with cover side flaps which can be engaged by suitable rails, thus, in a sense, suspending the rear portion of the box by its end wall. In addition, it is advantageous to square up the carton body by an appropriate squaring or jogging mechanism so constructed in relation to the supporting elements that the carton thereafter remains in its squared posit-ion during the step of application of adhesive to the flaps.

These and other features and advantages of this invention will appear more fully from the detailed description which follows accompanied by drawings showing, for the purpose of illustration, a preferred embodiment of the invention. The invention also resides in certain new and original features of construction and combination of elements hereinafter set forth and claimed.

Although the characteristic features of this invention which are believed to be novel will be particularly pointed out in the claims appended hereto, the invention itself, its objects and advantages, and the manner in which it 3,263,398 Patented August 2, 1966 may be carried out may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of it in which:

FIGS. 1 to 5 are perspective views of a machine incorporating the present invent-ion and illustrating five successive steps in the passage of a carton therethrough, the die portion of the machine being swung out of the Way for better visibility;

FIG. 6 is a perspective view of the machine of FIGS. 1 to 5 with the die portion in operative position;

FIGS. 7 to 10 are perspective views illustrating the transport and squaring of a carton during its passage into a position in line with the die, the top frame being shown slightly raised for the sake of clarity;

FIG. 11 is a perspective view down the die throat;

FIGS. 12 and 13 are perspective front and rear views of portions of the drive mechanism;

FIG. 14 is a diagrammatic illustration of the plunger servo-motor; and

FIGS. 15 and 16 are views illustrating the operation of a vent valve which forms a portion of the control mechanism of the pneumatic plunger.

In the following description and in the claims various details will be identified by specific names for convenience. The names, however, are intended to be generic in their application. Corresponding reference characters refer to corresponding parts in the several figures of the drawmgs.

The drawings accompanying, and forming part of, this specification disclose certain specific details of construction for the purpose of explanation of broader aspects of the invention, but it should be understood that structural details may be modified in various respects without departure from the principles of the invention, and that the invention may be incorporated in other structural forms than shown.

The machine shown in the drawings comprises a main frame 11 to which a top frame 12 is hingedly attached at 13. FIGS. 1-5 show the top frame in a raised position for convenient access to, and inspection of, certain parts of the machine mechanism. When swung down into operative position ('FIG. 6) lugs 14 of the top frame rest on posts 15 of the main frame fitted with locating pins 16.

A carton closing conveyor extends to the machine from the left. 'It comprises basically two conveyor chains 17, '18, fitted with the customary lugs for pushing cartons C along the conveyor track. The conveyor further comprises a pair of reciprocating pusher arms 19 for moving the cartons beyond the end of the reach of the conveyor chains 17, 18 against a stop 20 (FIG. 2).

Above the track of the carton closing conveyor carton cover folding elements are mounted which engage the carton cover and fold it down, as the carton moves to-- wards the stop. The cover folding elements comprise a series of rollers 21 mounted on a downwardly slanted rail 22, and hold down bars 23 pivotally mounted at 24, so as to permit the bars to be swung out of the way in the event a carton jam occurs under the bars.

When resting against the stop 20, the carton lies within the reach of a second conveyor whose chains 25, 26 are fitted with lugs 27 for advancing cartons along a second conveyor track, at right angles to the track of the first conveyor :17, 18, towards a plunger whose top plate is visible at 28. When moving along the conveyor track of the second conveyor the boxes slide on a track plate 29 which terminates at the plunger plate '28 and lies slightly higher than the plunger plate in the position in which the plunger is fully retracted, as it is in FIG. 1.

As the carton C moves along the conveyor track plate 29 is passes a guide bar 30 having a slanted forward position 31 (FIG. 1) for accurately orienting the carton on 3 the conveyor by urging the carton against the side of the stop 20.

The plunger plate is flanked laterally by two tanks 32, 33 for hot melt adhesive whose walls 34, 35 adjacent the plunger path are shaped as carton cove-r supporting elemeans comprising terminal horizontal portions 36 and inclined forward portions 37 for engaging and raising the cover of a carton which is being advanced to a position in line with the plunger to the level of the horizontal portions 36. As will later be seen, a carton is actually lifted and suspended by its rear wall when the cover rests on the horizontal portions 36.

Further supporting means are provided for the leading portion of a carton between the tanks 32 and 33. In the illustrated machine two substantially L-shaped bars 38 are mounted on the near wall 39 of a third adhesive tank 40. Each bar comprises a sloping forward portion 41 (best seen in FIG. ll), a horizontal support portion 42, and a vertical stop portion 43 against which the carton comes to rest.

The three adhesive tanks 32, 33 and are arranged substantially in the shape of a U adjacent the sides and the front of a carton resting on the supporting means.

Adhesive applicators in the shape of upwardly pointing fingers 44 are best seen in FIGS. 4 and 5, and are mounted on vertical holders 45 which, in turn, are attached to an adjustable U-shaped (framework comprising .a back portion 46 and lateral portions 47 clamped to the back portion at 48. Each end of the back portion is attached to an actuator post 49 (see also FIG. 13) which moves up and down and reciprocates the applicator fingers from a first low position in which they are submerged below the level of the adhesive in the tanks (FIG. 1) to a high position (FIG. 5) in which the tips of the fingers touch the cover flaps of a carton and transfer adhesive from the finger tips to the underside of the flaps. As also seen in FIG. 5, the fingers 44 are formed by notching the upper edge of a plate 50 attached to the vertical holders 45 by horizontal studs 51. In the position in which adhesive is being applied the carton is above and out of contact with the top plate 28 of the plunger, the leading front end of the carton being supported on the L-shaped supports 38, the rear wall of the carton being suspended from the carton cover resting on the lateral supporting elements 36 which engage the cover adjacent the side flap fold lines.

The machine is adjustable for cartons of different sizes. A change from one carton size to another may require a different setting of the adhesive applicators. In addition to the adjustment of the lateral arms 47 with respect to the back portion 46, such changes also involve a re setting of the stop and of the lateral tanks 32, 33. As seen in FIG. 5, the tank 33 is mounted on studs 52 on a horizontally adjustable mounting plate 53 to which also the stop '20 is secured by posts 54.

A similar adjustable plate on the opposite side of the conveyer supports the tank 32 and a bracket 55 carrying a hold down bar 56.

The track plate 29 is adjustable in a similar manner to permit installation of a larger plunger top plate 28. The track plate 29 is longitudinally slida-ble and is adjusted by means of bolt 57 secured at one end 58 to the main frame and extending with its other end through a boss 59 on the track plate. Nuts 60 lock the boss 59 with respect to the bolt 57.

Means are provided for accurately squaring the carton in its position above the plunger in which position adhesive is applied to the cover flaps.

In the illustrated form of machine the squaring mechanism is mounted on the top frame and comprises a pair of shoe plates 61 having upturned ends 62. The plates 61 are downwardly inclined (FIG. 7) and act as guides or hold down plates for a carton traveling on the conveyor 25, 26, 27, 29. The upturned ends are adapted to engage the trailing wall of the carton to push the carton 4 into its final position on the supporting elements, the L- shaped bars 38, in which position the cover rests on the horizontal supports 36, as previously described.

In order to perform this transporting and jogging (i.e., lining up and squaring) function, the shoe plates 61 are provided with a pendulous mounting of the parallelogram type. This mounting is best seen in FIG. 1 and comprises transverse bars 63 extending through bushings 64 in the shoe plates 61, arms 65 and pivot shafts 66, 67 (see also FIGS. 6 and 7) rotatably mounted in brackets 68 on the top frame.

One end of the pivot shaft 66 has an actuating arm 69 secured thereto carrying a roller 78 (FIG. 6), the other end carries a similar arm 71 to which a pull-back spring 72 is attached.

A lifter plate 73 on the end of a push rod 74 biased by a spring. 75 (FIG. 6) is underneath the roller '76 and causes the shoe assembly 61 to swing forward to advance and square a carton every time the push rod 74 is lifted.

The actuating mechanism for the push rod 74 is seen in FIG. 12 and comprises a bell crank lever 76 pivotally mounted on the main frame 11 at 77. The bell crank lever carries a roller 78 engaging the periphery of a cam 79 on a timing shaft 81). It is seen that the pull of the spring 75 urges the roller 78 against the cam 79.

It should be noted that in FIGS. 7 to 10 the top frame 12 is shown slightly raised in order to show the interior of the mechanism more clearly. For this purpose a block 81 was placed on the post 15. Properly lowered into the position in which the lug 14 rests on the post 15 (as it is shown in FIG. 6) the shoe plates 61 are in a slightly lower position. When taking the photographs from which FIGS. 7 to 10 were prepared it was found impossible to place the camera in any position in which essential elements of the mechanism would not be obscured by other elements when the top frame was lowered completely. Insertion of a spacer block relieved that difiiculty.

FIG. 7 shows the carton C in a position just prior to the withdrawal of the conveyor lugs 27. At this moment the push rod 74 (FIG. 6) begins its upward stroke and the lifter plate 73 makes contact with the roller 70. The shoe plates swing downward and forward, their upturned ends 62 engage the rear wall 82 of the carton and push the carton C forward (FIG. 8) into its proper position above the plunger plate 28 and squaring the carton at the same time. It will be noted that in FIG. 8 the conveyor lugs have been withdrawn below the level of the track plate 29.

FIGS. 9 and 10 show the mechanism during its return stroke. During this period (FIG. 9) a second carton C is arriving from the left, and the pusher arms 19 are about to engage it to push it against the stop 20.

FIG. 10 shows the squaring mechanism. fully retracted. For this illustration the cartons were removed from the machine to show the relative position of the various elements. The plunger top plate 28 is at a lower level than the track plate 29. The horizontal supporting portions 36 of the L-shaped supporting bars 38 are above the plunger top plate 28, but their forward inclined portions 37 extend to a level below the top plate 28.

The relative position of the cartons and elements of the machine in FIG. 8 corresponds to that shown in FIG. 5 except for the fact that the top frame 12 is swung out of the way in FIG. 5. At the illustrated instant the adhesive applicator plates 50 (FIG. 5) are moving upwardly. They make contact with the cover flaps at about the instant shown in FIG. 9. At this moment the shoe plates 61 are being retracted, as can also be seen by comparing the position of the roller 76 and lifter plate 73 in relation to the top frame 12 with the position shown in FIGS. 8 and 9.

At about the moment shown in FIG. 9 the carton C is ready to be lifted by the plunger and driven into the flap folding and compression die which will now be described.

The construction of the die is best seen in FIGS. 1 and 11. A die throat of rectangular cross section is formed by four die walls of which at least onein the event only one cover flap is to be adhered-and preferably three-in the event three cover flaps are to be adhered-are made resilient.

Referring to FIG. 11, a solid back plate 83 is mounted on a bracket 84 and is fitted with vertical contact rails or bars 85.

The opposite portion of the die comprises a bracket 86 supporting an upright plate 87 to which a plurality of vertical contact rails 88 are yieldingly secured. For this purpose each rail has two stems 89 extending through bores in the plate, a compression spring 90 on each stem, and a nut 91 for holding the stern and bar in place and permit minor adjustment of the bar towards and away from the die axis.

The lateral portions of the die are identically constructed, except for dimensions, as the die portion last described. Brackets 92 and 93 support vertical plates 94, 95. The plates 94, 95 are fitted with contact rails 88 backed by springs 90 and secured by nuts 91. The bottom ends of the rails 88 are preferably beveled, as best seen in FIG. 6.

The size of the die is adjustable for cartons of different sizes by setting die walls closer to, or farther away from, the die axis. For this purpose each bracket is slotted, as at 96, and clamped in place by a bolt 97 extending into the top frame 12.

The entrance portion of the die comprises outwardly flared plates 98 and resilient rollers 99 between the plates 98 and the contact or pressure rails 88, and is best seen in FIG. 1.

After application of adhesive to a carton, the carton is driven by the plunger into the die and remains therein for a time suflicient to permit the adhesive to set. As shown in FIG. 6, the illustrated form of die has a capacity of about three cartons. In order to prevent the lowermost carton from dropping out under the weight of the cartons above it, catches 100 are provided which are best seen in FIGS. 1 and 11. These catches recede under spring tension when a carton is pushed into the die and snap into a locking position as soon as the carton has cleared it.

In the event the carton bulges at different points within the side walls as a result of the pressure of the carton contents on the walls, the respective contact rail 88 in line with the bulge yields. In this manner even sealing pressure is maintained over the entire area of the side walls to which the cover flaps are sealed.

The plunger top plate 28 is mounted on the plunger head 101 of a pneumatic servo-motor shown diagrammatically with its controls in FIG. 14. The servo-motor comprises a pneumatic cylinder 102 in which a piston 103 is movable. The plunger head 101 is secured to the end of the piston rod 104 to which also a control rod 105 is attached. An adjusable collar 106 on the control rod serves to actuate a pilot valve 107 after the plunger has traveled a predetermined distance. From valve 107 a duct 108 leads to a pilot cylinder 110-A of an assembly comprising pilot cylinder units 110-A, 110-B whose pistons operate a spool valve 111.

An air pressure supply duct extends from a suitable source of compressed air (not shown) to the spool valve 111 and thence duct 113 leads to the lower chamber 109 of the cylinder 102. Restricted branch ducts 113' supply air to pilot cylinder units 110-A and 110B. Normally the pressure in unit 110-A is equal to the pressure in unit 110-B. For this reason the spool valve 111 will remain in the .position in which it happens to -be until the balance of pressures is disturbed.

Assuming that the spool valve is in the position shown in FIG. 14, compressed air enters the lower cylinder 6 chamber 109 driving the piston 103 upwardly, while air from the upper cylinder chamber 209 escapes to the atmosphere through line 213 via the spool valve. When the piston 103 has risen far enough to cause the collar 106 to actuate the valve 107, air is vented from the chamber of pilot A. The pilot pressures are unbalanced and the expanding air in unit 110B causes the spool valve to shift to the left. The shift of the spool valve causes compressed air to enter the upper cylinder chamber 209 via the crossover in the spool valve, while air escapes from the lower chamber 109 to the atmosphere.

Pressure will be maintained in the top chamber 209, and the piston 103 (and also the plunger top plate 28) will remain in the bottom position until a further pilot valve 112 is actuated and bleeds air from the chamber of pilot unit 110B. Then the spool valve shifts to the right and the piston 103 is driven upwardly as described.

The valve 112 is designed briefly to vent air during a moment of predetermined duration, regardless of machine speed, and is shown in FIGS. 15 and 16.

The valve proper 114 has a control stem 115 protruding from its housing and is actuated by any one of three rollers 116 mounted on a common cylindrical disc 117 rotatable about an axis 118 in the control valve support 119. The adjustment of the rollers relatively to the stem 115 is such that upon rotation of the disc the roller passing the stem 115 depresses it and actuates the valve to vent air from a line connected to duct fitting 120.

An arm 121 on a tilt shaft 122 biased by a spring 123 normally maintains the rollers in the position shown in FIG. 15. In this position the roller nearest the stem 115 clears it and the valve is closed.

If now the cluster of rollers is rotated by a force F exerted on the hub of the protruding roller, the roller cluster turns counterclockwisely about its axis 118 and deflects the arm 121 (FIG. 16).

As soon as the over-center position is reached between the arm and the roller on whose periphery the arm bears, the roller assembly snaps under the spring tension into the next rest position, differing degrees from the previous rest position. About 20 degrees before arriving at the new rest position the roller next in sequence passes the valve stem and causes the valve to be opened for a fraction of a second to vent air during a moment of predetermined duration.

The element which actuates the valve assembly is a control arm 124 on the timing shaft 80. As seen in FIG. 13 the arm depresses the exposed roller by engaging it at the hub to exert the actuating force F.

Should for any reason the machine be turned backwards, by hand or otherwise, the valve assembly will not be actuated, but is tilted about a tilt axis 125 towards the observer of FIG. 13 into an inoperative position.

Turning now to the mechanical drive of the machine, the shaft126 may be considered the power input shaft. In the illustrated installation the shaft 126 is the output shaft of a right angle drive 127 installed at the end of the conveyor unit comprising conveyor chains 17 and 18 which feed cartons from the left (FIG. 1). The carton closer thus is driven *by the supply conveyor unit.

The sprocket gear 128 on the shaft 126 drives the timing shaft 80 by a chain 129 trained around a sprocket gear 130 (FIG. 13) on the timing shaft-80.

As shown in FIG. 12, a further sprocket gear 131 on the shaft 80 drives a sprocket gear 134 which forms a portion of a double sprocket unit 134, 140, rotatable on a fixed shaft 132. The chain 133 is upwardly deflected between the shafts 80 and 132 and is trained over an idler gear 135 on an idler shaft 136 vertically adjustable between mounting plates 137 and 138 to compensate for chain Wear.

The conveyor chains 25 and 26 (FIG. 1) which move the cartons towards the plunger and die portion of the machine are driven by a vertical chain 139 trained around a second sprocket gear 140 of the double sprocket unit 7 134, 140. The upper loop of the vertical drive chain 139 is hidden partially by the track plate 29 and partially by a cover plate 141 (FIG. 1).

A large cam 142 on the timing shaft 80 acts on a cam follower roller 143. The roller is mounted between two parallel plates 144, 145. The plates 144, 145, in turn, are secured to a long lever constructed from two parallel plates 146. The near end of the lever 146 is pivotally mounted on the main frame 11 (the pivot being obscured and not visible). The far end of the lever 146 actuates the actuator post 49 of the adhesive applicator. There are two levers, one for each of the two actuator posts. In FIG. 12 only one lever 144, 145 is visible on the right, the other lever on the left being obscured by the right angle drive 127. Looking at the machine from the rear (FIG. 13) the end of the other lever 144, 145 is visible, but the one lever is beyond the range of the figure The two levers are interconnected by a rod 147 which is pulled in an upward direction by a spring 148 in order to keep the roller 143 in contact with the periphery of the cam 142.

The pneumatic servo-motor 101, 102, 104 is mounted inside a U channel 149 (FIG. 13) to which a tapped boss 150 is secured. A threaded spindle 151 extends through the boss 150 and is fitted at its upper end with a socket 155 for adjustment of the servo-motor in a vertical direction.

After adjustment the channel 149 is clamped in position by a clamp 152 visible to the left of a drain nipple 153 for draining the adhesive tank 40. The adhesive tanks are electrically heated for the use of hot melt adhesives, the heat control box for the three tanks being visible at 154 in FIG. 1.

Summary of operation Filled cartons C advance toward the closing machine from the left in FIG. 1. The cartons are moved by the conveyor 17, 18 and travel under overhead cover closing means 21, 23 which fold the carton cover down flat upon the carton body. During the terminal portion of the conveyor track where the transporting lugs on the chains are about to disengage from the carton oscillating pusher arms 19 take over and advance the carton against a front stop 20 in which position the carton is within the reach of a second conveyor 25, 26 for transport at right angles with respect to its previous direction of travel (FIGS. 1 and 2).

The lugs 27 of the second conveyor advance the carton towards a plunger whose top plate is visible at 28 (FIGS. 3 and 4).

During the final portion of its travel the carton C is grasped by shoe plates 61 on the top frame 12 which advance the carton into a position in which the carton is supported or suspended above the plunger top plate by L-shaped support bars 38 at the front, and by lateral supports 36 engaging the underside of the cover at about the side flap fold lines. Simultaneously the carton is accurately squared (FIGS. and 9). At this moment a second carton C approaches the stop 20.

The shoe plates 61 are actuated over a linkage 63, 65, 66, 69 by a cam operated push rod 74 (FIG. 6) which is raised and lowered periodically.

While in squared position hot melt adhesive from tanks 32, 33 and 40 (FIG. 5) is applied to the underside of the carton cover side flaps by applicator plates 51} (FIG. 5) having serrated top edges to form applicator fingers, the tips of which transfer adhesive to the cover flaps. The applicators are jointly operated by a framework 46, 47 periodically raised and lowered by cam operate-d actuator posts 49, timed in their operation with respect to the conveyors and the push rod 74, there being a common drive for all.

After application of adhesive a pneumatic servo-motor is actuated to lift the carton into the throat of a compression die in the top frame 12 (FIG. 6). Other views of the die are in FIGS. 1 and 11. The die throat is lined by spring-urged bars which adjust themselves individually to irregularities in the carton shape, such as bulges caused by irregularly shaped carton contents.

The servo-motor receives a timed blast of compressed air from a control valve (FIGS. 15, 16) designed to operate independently of the machine by employing an over-center snap action. Compressed air supplied to the cylinder 102 of the servo-motor (FIG. 14) is automatically vented by a vent valve 107 (FIGS. 12-14) after the plunger has traversed a predetermined stroke, whereafter the plunger plate 23 returns to its normal retracted position. Immediately thereafter the next carton C arrives and the cycle is repeated.

What is claimed is:

1. A carton sealing machine comprising, in combina tion, a plunger having a top surface adapted to engage the bottom panel of a carton to be sealed; a die in line with, and above, the plunger, the die comprising at least two opposite wall elements defining a die throat between them, at least one of said elements being resiliently movable in a direction to exert compressive force on the walls of a carton in said die; carton supporting means underneath said die for supporting a carton in a position in which the carton bottom wall is spaced above the top surface of the plunger when the plunger is retracted, said supporting means comprising at least one element for engaging the carton bottom adjacent its leading edge and a further element for supporting the carton by its trailing wall; a conveyor for moving cartons towards said plunger; a reciprocating pusher for engaging the trailing portion of the carton and moving it from said conveyor into engagement with said supporting means; adhesive applying means alongside said supporting means for applying adhesive to the cover flap of a carton on said supporting means; and power means for operating said plunger, pusher, and applying means in timed relationship.

2. A carton sealing machine comprising, in combination, a plunger having a top surface adapted to engage the bottom panel of a carton to be sealed; a die in line with, and above, the plunger, the die comprising at least two opposite wall elements defining a die throat between them, at least one of said elements being resiliently movable in a direction to exert compressive force on the walls of a carton in said die; carton supporting means underneath said die for supporting a carton in a position in which the carton bottom wall is spaced above the top surface of the plunger when the plunger is retracted, said supporting means comprising at least one element for engaging the carton bottom adjacent its leading edge and a further element for supporting the carton by its trailing wall; transport means for moving a carton to be sealed onto said supporting means; adhesive applying means alongside said supporting means for applying adhesive to the cover flap of a carton on said supporting means; and power means for operating said plunger, transport means and applying means in time relationship.

3. A carton sealing machine comprising, in combinatlon, a plunger having a top surface adapted to engage the bottom panel of a carton to be sealed; a die in line with, and above, the plunger, the die comprising at least two opposite wall elements defining a die throat between them, at least one of said elements being resiliently movable in a direction to exert compressive force on the walls of a carton in said die; means for periodically moving said plunger into and out of the throat of said die; carton supporting means underneath the said die for supporting the carton to be sealed by its leading front wall and its leading back wall, said front wall engaging means comprising an element for engaging the carton bottom adjacent its front edge, said back wall supporting means comprising a pair of elements extending substantially parallel to the carton sides and engaging the carton cover adjacent the cover side flap fold lines, thereby suspending the rear wall by said cover, the supporting means being so positioned with respect to said plunger as to support the carton at a distance above said plunger when the plunger is in its retracted position; a conveyor for moving cartons toward said plunger; a reciprocating pusher for engaging the trailing portion of the carton and moving it from said conveyor into engagement with said supporting means; adhesive applying means along side said supporting means for applying adhesive to the cover flap of a carton on said supporting means; and power means for operating said plunger, pusher, and applying means in timed relationship.

4. A machine for scaling to the front and side walls of a carton the front and side flaps of the hinge cover of the carton, the machine comprising, in combination, a plunger having a top surface adapted to engage the bottom panel of the carton; a die in line with, and above, the plunger, the die comprising opposite wall elements defining a die throat between them and adapted to exert compressive force on the sides of a carton within the throat; means for periodically moving said plunger into and out of the throat of the die; carton supporting means underneath the die for supporting a carton in a position in which the carton bottom wall is spaced above the top surface of the plunger when the plunger is retracted, said supporting means comprising 'at least one element for engaging the carton bottom adjacent the carton front wall, and a pair of elements extending substantially parallel to the carton sides for engaging the carton cover adjacent the cover side flap fold lines, thereby suspending the carton rear wall by the cover; transport means for moving a carton to be sealed into engagement with said supporting means; adhesive applying means alongside said supporting means, said adhesive applying means comprising a receptacle for liquid adhesive and an applicator movable from a position in which it is submerged below the level of the adhesive in the receptacle into a position of contact with the cover flaps; and power means for operating said plunger, transport means and applying means in timed relationship.

5. A machine for sealing to the front and side Walls of a carton the front and side flaps of the hinge cover of the carton, the machine comprising, in combination, a plunger having a top surface adapted to engage the bottom panel of the canton; a die in line with, and above, the plunger, the die comprising opposite \wall elements defining a die throat between them and adapted to exert compressive force on the sides of a carton within the throat; means for periodically moving said plunger into and out of the throat of the die; carton supporting means underneath the die for supporting a carton in a position in which the carton bottom wall is spaced above the top surface of the plunger when the plunger is retracted; a pair of elements extending substantially parallel to the sides of a carton above the plunger for engaging the underside of the carton cover adjacent the cover side flap fold lines; hold-down means above said elements for engaging the top side of the carton cover, said elements and hold-down means forming a gap between them in which the carton cover with extended cover flaps is held with limited freedom of vertical movement; transport means for moving a carton to be sealed onto said supporting means and with its cover between said elements and hold-down means; adhesive applying means alongside said elements, said adhesive applying means comprising a receptacle for liquid adhesive and an applicator movable from a position in which it is submerged below the level of the adhesive in the receptacle into a position of contact with the cover flaps; and power means for operating said plunger, transport means and applying means in timed relationship.

6. A machine for sealing a carton by adhesively securing a flap articulated to the carton cover to the carton eases side, the machine comprising, in combination, a plunger having a top surface adapted to engage the bottom panel of a carton to be sealed; a die structure in line with, and above, the plunger, the die comprising a plurality of pressure bars parallel to the plunger axis and arranged along at least two sides of a rectangle of a size corresponding to the size of the carton to be sealed, said bars being yieldingly mounted to exert compressive force on the carton sides with freedom of the bars individually to adjust to bulges in the carton walls, the die forming a throat passage into which cartons may be moved by said plunger; carton supporting means for supporting a carton above the top surface of the plunger when the plunger is retracted; transport means for moving cartons individually onto said supporting means; adhesive applying means positioned to apply adhesive to the cover flaps of a carton on said supporting means; and power means for operating said transport means, said adhesive applying means and said plunger in timed relationship.

7. A machine for sealing a carton by adhesively securing a flap articulated to the carton cover to the carton side, the machine comprising, in combination, a plunger having a top surface adapted to engage the bottom panel of a carton to be sealed; a die structure in line with, and above, the plunger, the die comprising a four sided structure enclosing a rectangular space, three sides of which are formed by pressure bars arranged in the manner of a cage; the bars being parallel to the path of the plunger and yieldingly mounted to exert compressive force on the sides of a carton moved by the plunger into said rectangular space with freedom of the bars individually to adjust to bulges in the carton walls; carton supporting means for supporting a carton above the top surface of the plunger when the plunger is retracted and underneath said cage structure; transport means for moving cartons individually onto said supporting means; adhesive applying means along three sides of the position of a carton on said supporting means, said applying means comprising a receptacle and an applicator movable from a first position in which it is submerged in the pool of adhesive in the receptacle into a second position in which it contacts the underside of the respective cover fiap of a carton on said supporting means; and power means for operating said transport means, said adhesive applying means, and said plunger in timed relationship.

8. A machine for sealing a carton by adhesively securing a flap articulated to the carton cover to the carton side, the machine comprising, in combination, a plunger having a top surface adapted to engage the bottom panel of a carton to be sealed; a die structure in line with, and above, the plunger, the die comprising a four sided wall structure enclosing a rectangular space, one side of the rectangle being formed by a solid wall adapted to engage the rear wall of the carton to which rear wall the cover is articulated, the three remaining sides of the rectangle being formed by yielding substantially parallel bars for exerting compressive force on the other three walls of the carton to which cover flaps are to be adhered; carton supporting means for supporting a carton above the top surface of the plunger when the plunger is retracted and underneath said die; transport means for moving said cartons individually onto said supporting means; adhesive applying means along three sides of the position of the carton on said supporting means for applying adhesive to the three cover flaps of the carton; and power means for operating said transport means, said adhesive applying means and said plunger in timed relationship.

9. A machine for sealing a carton by adhesively securing a flap articulated to the hinge cover of the carton to the carton side, the machine comprising, in combination, a main frame; a plunger mounted on the main frame, said plunger having a top surface adapted to engage the hottom panel of a carton to be sealed and elevate the carton into the die throat hereinafter recited; carton supporting means on said main frame for engag- 

2. A CARTON SEALING MACHINE COMPRISING, IN COMBINATION, A PLUNGER HAVING A TOP SURFACE ADAPTED TO ENGAGE THE BOTTOM PANEL OF A CARTON TO BE SEALED; A DIE IN LINE WITH, AND ABOVE, THE PLUNGER, THE DIE COMPRISING AT LEAST TWO OPPOSITE WALL ELEMENTS DEFINING A DIE THROAT BETWEEN THEM, AT LEAST ONE OF SAID ELEMENTS BEING RESILIENTLY MOVABLE IN A DIRECTION TO EXERT COMPRESSIVE FORCE ON THE WALLS OF A CARTON IN SAID DIE; CARTON SUPPORTING MEANS UNDERNEATH SAID DIE FOR SUPPORTING A CARTON IN A POSITION IN WHICH THE CARTON BOTTOM WALL IS SPACED ABOVE THE TOP SURFACE OF THE PLUNGER WHEN THE PLUNGER IS RETRACTED, SAID SUPPORTING MEANS COMPRISING AT LEAST ONE ELEMENT FOR ENGAGING THE CARTON BOTTOM ADJACENT ITS LEADING EDGE AND A FURTHER ELEMENT FOR SUPPORTING THE CARTON 